Non-contact wireless electric power transmission without using a power supply cord or an electric power transmission cable has recently attracted attention, and application to an electric car or a hybrid vehicle in which a car-mounted power storage device can be charged by a power supply outside a vehicle (hereinafter also referred to as an “external power supply”) has been proposed.
Japanese Patent Laying-Open No. 2011-250555 (PTD 1) discloses an electric power feed system for supplying electric power in a non-contact manner to a vehicle from an electric power feed facility outside the vehicle, in which information such as charging efficiency or an amount of charge is conveyed between the electric power feed facility and the vehicle through radio communication and appropriate charging is carried out based on such information.